The present application relates generally to the field of suspension systems for vehicles. More specifically, the present application relates to hydraulic dampers. Dampers (i.e. dashpots, hydraulic shock absorbers, etc.) dissipate kinetic energy as part of a vehicle suspension system. Dampers often include a housing, end caps, a piston, and a rod that is coupled to the piston. Energy is dissipated through a hydraulic fluid flow along a hydraulic circuit (e.g., between a first chamber within the housing to a second chamber within the housing). The piston includes a plurality of orifices that are covered with a shim stack (i.e. a plurality of compressed shims). As the piston moves through the housing, hydraulic fluid is forced from the first chamber, through the piston, and into the second chamber. Specifically, pressurized hydraulic fluid is forced through the orifices within the piston, deflects a portion of the shims to create an opening, and flows into the second chamber by passing through the opening. Such traditional dampers provide a damping force that does not vary based on the location of the piston along the length of the housing.
Traditional vehicle suspension systems incorporate/these dampers and other devices as part of a suspension damping strategy. By way of example, the vehicle suspension may also include a spring coupled in parallel with the damper to a swing arm. In jounce, the damper and the spring are compressed, and the damper imparts a resistive force. Such a vehicle suspension strategy results in large total force that is transmitted to the occupants of the vehicle.